Gotta do better

[somdlt4]

OK guys, I took my "new" '96 LT4 to the track last night. I'm not the best driver in the world but I've spent a lot of time on 1/4 mile tracks, so I'm adequate. The best I could do was 14.18 at 97mph. Very disappointing. I was launching at about 2500-3000 and it hooked up pretty well. Ran good, just seemed to lack punch at the top end.

To make matters worse, I got beat by a Mustang.........(he WAS using Nitrous).

What do I do to get into the 13's at least. My pockets are not real deep, so I need the most bang for the buck.

Any suggestions are appreciated. Thanks

 

[stgry1]

Wow. That is disappointing my friend. Even stock tests in 96 had runs in the 13s. Is you car completely stock? If it is running as it should, the only thing I could say would be traction is the culprit. Post your 60ft times....

 

[Vettefan87]

What is the elevation of the track? What are your 60 ft times. Something tells me your car is not running right depending on elevation of the track. Yesterday my fairly stock 87 ran 13.8 @ 99 mph. Was the track conditions like a test and tune, where reaction time doesn't count?

 

[somdlt4]

Thanks for the replys. I made 3 passes. 60 ft. times were: 2.486, 2.418, and 2.262.

 

[Edmond]

Don't worry, get out there and practice.

 

[Vettelt193]

60' times are a bit slow, but worse is your MPH. if you run in the 14's but over 100 MPH, you know you are doing something wrong... but under 100 might mean you aren't putting down the power.

To find out, try to sport shift 1st and 2nd, and power 3rd (and 4th if you are even getting into it?) I would shift around 4k out of 1st + 2nd. if your MPH goes up, at least you know you have the power, and it is driver error... then all you gotta do is practice. if it doesn't go up much, you may want to start checking the car out...

 

[Vettefan87]

Yeah his car should trap well over 100 mph. What are you shifting at? Even though your sixty foot times are bad that should mean your trap would even be higher.

 

[DRTH VTR]

Yeah his car should trap well over 100 mph. What are you shifting at? Even though your sixty foot times are bad that should mean your trap would even be higher.

I have also noticed that when I get too much wheelspin at launch, my trap speed may be higher, and that when I get a good 60' time, my trap speed can be a bit lower. Not by much; just a little bit.

I think that 60' times of 2.1 to 2.0 on street tires are attainable. I get 1.8-1.9 on drag radials. I suspect that you are spinning too much. Also, for what it is worth, the reaction time NEVER matters in the elapsed time. They are independent of each other. You can sit at the tree for 5 seconds and still run the same ET as when you get a good light. The starting line is about 18" in front of the staging beam, and ET does not start until you break the starting line beam.

I had a stock '97 A4 that ran 14.2 @ 104 at 2600'. The few LT4's that I saw run at that track were faster than I was. Practice the launches with a lighter touch on the throttle and see what happens. If you hear your tires screeching, you are getting too much spin. Spin is slow.

Just my $0.02- Have fun and get some practice. You will get under 14 seconds.

 

[Vettefan87]

Yeah I think the only time reaction time is factored in, is when they are doing brackets and eliminations. At my local track on Friday night it is all just Test & Tune from 4:30 till dark. My best 60 ft was 2.0 with deacent amount of tire spin. First time at the track, first run ever I ran 13.8 @ 99 mph. I thought my car would run a little better with the headers and what not, but I am not complaining.

 

[somdlt4]

Thanks for the replys. Maybe I can get the 60 ft. time a little better if I lower the rear tire pressure a little. As far as shift points; I was shifting around 5500. The car seems very strong; I guess that's why I was disappointed with the 14.2's. I was sure it was a 13 second car. Do you guys run with the traction control on or off?

Thanks again.

 

[stang-etr96]

Traction control OFF !!!!!!! also make sure to ture off A/C. My LT4 runs 13.2/13.3 at 106/104 mph with 2.1/2.2 60 ft times. Stock tires, open air box, K&N, camber exhuast. Pretty much stock and I'm not a drag racer. I have to lanuch at around 1800 rpm to get the stock tires from burning off the rim. Just my .02

 

[jcs44]

To take this one step further - for all you guys who race regularly, I'd like to hear your opinions on what's best for a good time:
ASR on or Off?
Launch RPM
Shift points
Tire pressure (stock tires)
Wheel spin
Other advice?

Thanks, JCS44, LT4 Vert, Blk/Blk

 

[DRTH VTR]

To take this one step further - for all you guys who race regularly, I'd like to hear your opinions on what's best for a good time:
ASR on or Off?
Launch RPM
Shift points
Tire pressure (stock tires)
Wheel spin
Other advice?

Thanks, JCS44, LT4 Vert, Blk/Blk

ASR off, for sure.

Drive around the water box. Spin the tires a little, just to clean off any sand and pebbles picked up by the traction compound left on your tires, then stage.

Launch RPM will require some trial and error. I launch at about 4000 RPM, but I run drag radials. I would think 2500 is closer with street tires. The thing that it is very tempting to do is to drop the clutch and floor the gas pedal. It will result in excessive spin. I would suggest a slightly more gradual application of throttle. You will have to practice. It is a fine line between too much spin and bogging the engine.

For shift points, I have a Z06 and take it to red line in every gear. There are some C4's (L98?) that run out of breath before red line, but I don't think that is the case with the LT4. I would suggest taking it right to red line..

There are many people who suggest dropping the tire pressure to about 15 lbs in street tires. That is what I run in my drag radials. However, I am not convinced that it makes that much difference in a street tire with a fairly stiff sidewall. Just my opinion.

I know that you are out to get some better times. I certainly understand that. But if you are bracket racing, consistency and good reaction times are what wins races.

About the et and rt: They are always independent of each other. However, it is obvious that if 2 cars both run an et of 13 seconds, the car with the slow reaction time will get to the finish line in second place. If you watch drag racing on TV, you will see a slower et beat a faster et. This is due to a better rt, where the faster reaction time wins in a "hole shot".

I hope this helps some. See my avatar. That is me at my local strip.

Jim

 

[jcs44]

That sounds like good stuff Vader. Thanks!

 

[Vettelt193]

the way to go really fast is to roll into the throttle as you roll off the clutch... almost using the clutch as a reverse gas pedal until it is all the way let out, while keeping the RPM's higher to stay at max power.

in the real world, forget about that, unless you have deep pockets and like to change clutches out frequently... but, the idea still needs to stay the same. you should launch at a higher RPM and roll off the clutch and into the throttle.

Shift points after launch depend on what you are going for... ET? rev it out. MPH? sport shift out of 1st and 2nd, so you spend more time in 3rd + 4th. that gets your MPH up, at the sacrifice of some time. But, i always suggest sport shifting the car for the first couple times at the track. It allows you to work on the launch, then it allows you to see if the car is putting out the power it should. Sport shifting should yeild a decent MPH even with a crappy launch. if it doesn't: you have to figure out what is 'wrong' with the car before racing anymore. I would still suggest a good 3 sport shift runs, shifting around 4k out of 1-2 before realizing the car isn't running right though.

 

[Greg@NASA]

I've never been to the track (gotta get to Houston Raceway Park some Fri. nite), but impromptu drags nearby have given me my quickest passes with ASR OFF,feather clutch @ 2200 r.p.m, and shifting @ 6K......hitting traps in 3rd gear just as rev limiter cuts in.Just my $0.02

 

[Paul G]

I took my CE to the track this summer. It was my first time at the track. My best run was my fourth time down the track, 13.154 @ 106.13 MPH, .939 reaction time, 1.91 60'. I launched at around 2000 RPM. Let the clutch out easy so not to spin the tires and then hammer it. ASR off or it you will cut back the power when the wheels spin grabbing second gear. Let them spin when grabbing second, it is better than cutting back on throttle. You definately need practice on that 60' time.

I found my AFPR was set at 39 pounds. Since my time at the track I turned it up to 47 pounds and the car feels much stronger as well as my fuel mileage went up.

My first run was a 14.0 with my wife in the car and the Power Effects mufflers closed. So it looks like your car should have a whole lot more in it than you are getting right now.

 

[somdlt4]

Paul,

I found my AFPR was set at 39 pounds.

Probably a dumb question but, what's AFPR?

Thanks for the reply,

John

 

[Edmond]

adjustable fuel pressure regulator.

No such thing as a dumb question here!